So I was playing around with an earlier version of Famitracker and was basically having fun with the MMC5 and VRC6 in PAL mode. What I do know is that the MMC5 is also using PAL pitch table periods, wile the VRC6 literally forces everything to use an NTSC pitch table period in NSF export. Personally it doesn't bother me if my VRC6 NSFs are a semitone lower compared to Famitracker's output.